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 Author:
 George, A. W.; Mengersen, K. L.; Davis, G. P.
 Source:
 Biometrics 1999 v.55 no.2 pp. 419429
 ISSN:
 0006341X
 Subject:
 Markov chain; algorithms; biometry; genes; progeny
 Abstract:
 ... A technique is presented whereby a marker map can be constructed using resource family data with an entire class of missing data. The focus is on a halfâsib design where there is only information on a single parent and its progeny. A Bayesian approach is utilised with solutions obtained via a Markov chain Monte Carlo algorithm. Features of the approach include the capacity to determine parameter ...
 DOI:
 10.1111/j.0006341X.1999.00419.x

http://dx.doi.org/10.1111/j.0006341X.1999.00419.x
 Author:
 Walker, Stephen; Mallick, Bani K.
 Source:
 Biometrics 1999 v.55 no.2 pp. 477483
 ISSN:
 0006341X
 Subject:
 Markov chain; algorithms; biometry; models
 Abstract:
 ... A Bayesian semiparametric approach is described for an accelerated failure time model. The error distribution is assigned a Polya tree prior and the regression parameters a noninformative hierarchical prior. Two cases are considered: the first assumes error terms are exchangeable; the second assumes that error terms are partially exchangeable. A Markov chain Monte Carlo algorithm is described to o ...
 DOI:
 10.1111/j.0006341X.1999.00477.x

http://dx.doi.org/10.1111/j.0006341X.1999.00477.x
 Author:
 Quan, Hui; Capizzi, Thomas
 Source:
 Biometrics 1999 v.55 no.2 pp. 460462
 ISSN:
 0006341X
 Subject:
 biometry; clinical trials; safety assessment
 Abstract:
 ... Studies using a series of increasing doses of a compound, including a zero dose control, are often conducted to study the effect of the compound on the response of interest. For a oneâway design, Tukey et al. {1985, Biometrics41, 295â301) suggested assessing trend by examining the slopes of regression lines under arithmetic, ordinal, and arithmeticâlogarithmic dose scalings. They reported th ...
 DOI:
 10.1111/j.0006341X.1999.00460.x

http://dx.doi.org/10.1111/j.0006341X.1999.00460.x
 Author:
 Parzen, Michael; Lipsitz, Stuart R.
 Source:
 Biometrics 1999 v.55 no.2 pp. 580584
 ISSN:
 0006341X
 Subject:
 biometry; death; liver cirrhosis; liver transplant; models; regression analysis
 Abstract:
 ... In this paper, a global goodnessâofâfit test statistic for a Cox regression model, which has an approximate chiâsquared distribution when the model has been correctly specified, is proposed. Our goodnessâofâfit statistic is global and has power to detect if interactions or higher order powers of covariates in the model are needed. The proposed statistic is similar to the Hosmer and Lemes ...
 DOI:
 10.1111/j.0006341X.1999.00580.x

http://dx.doi.org/10.1111/j.0006341X.1999.00580.x
 Author:
 Stanley, Thomas R.; Burnham, Kenneth P.
 Source:
 Biometrics 1999 v.55 no.2 pp. 366375
 ISSN:
 0006341X
 Subject:
 Monte Carlo method; animal ecology; biometry; models
 Abstract:
 ... A new, fully efficient goodnessâofâfit test for the timeâspecific closedâpopulation captureârecapture model Mt is presented. This test is based on the residual distribution of the capture history data given the maximum likelihood parameter estimates under model Mt, is partitioned into informative components, and is based on chiâsquare statistics. Comparison of this test with Leslie's t ...
 DOI:
 10.1111/j.0006341X.1999.00366.x

http://dx.doi.org/10.1111/j.0006341X.1999.00366.x
 Author:
 Rongling, Wu; Li, Bailian
 Source:
 Biometrics 1999 v.55 no.2 pp. 355365
 ISSN:
 0006341X
 Subject:
 alleles; animals; biometry; clones; epistasis; evolution; family structure; forest trees; gene frequency; heterozygosity; hybrids; interspecific variation; loci; models; outcrossing
 Abstract:
 ... Epistasis may play an important role in evolution and speciation. Under multiplicative interactions between different loci, an analytical model is proposed to estimate genetic parameters at the individual locus level that contribute to interspecific differences in outcrossing species. The multiplicative epistasis model, inferred from a number of animal and plant experiments, suggests that genotype ...
 DOI:
 10.1111/j.0006341X.1999.00355.x

http://dx.doi.org/10.1111/j.0006341X.1999.00355.x
 Author:
 Zhang, Heping
 Source:
 Biometrics 1999 v.55 no.2 pp. 452459
 ISSN:
 0006341X
 Subject:
 biometry; body weight; cocaine; covariance; data collection; infant growth; retrospective studies; women
 Abstract:
 ... In this paper, we study the effect of cocaine use by a pregnant woman on the growth of her infant after birth. Using a data set from a retrospective study, we found that cocaine use was a marginally significant contributor to the infant growth as measured by bodyweight. Prom a statistical point of view, the data represent a common, though complex, structure that has received little: attention in t ...
 DOI:
 10.1111/j.0006341X.1999.00452.x

http://dx.doi.org/10.1111/j.0006341X.1999.00452.x
 Author:
 Brookmeyer, Ron
 Source:
 Biometrics 1999 v.55 no.2 pp. 608612
 ISSN:
 0006341X
 Subject:
 HIV infections; RNA; biometry; cost effectiveness; disease incidence; disease prevalence; polymerase chain reaction; variance
 Abstract:
 ... The testing of pooled samples of biological specimens for the purpose of estimating disease prevalence may be more cost effective than testing individual samples, particularly if the prevalence of disease is low. Multistage pooling studies involve testing pools and then sequentially subdividing and testing the positive pools. A simple estimator of disease prevalence and its variance are derived fo ...
 DOI:
 10.1111/j.0006341X.1999.00608.x

http://dx.doi.org/10.1111/j.0006341X.1999.00608.x
 Author:
 Berlin, Jesse A.; Kimmel, Stephen E.; Have, Thomas R. Ten; Sammel, Mary D.
 Source:
 Biometrics 1999 v.55 no.2 pp. 470476
 ISSN:
 0006341X
 Subject:
 atherosclerosis; biometry; blood vessels; cost effectiveness; models; odds ratio; patients; risk
 Abstract:
 ... In the analysis of binary response data from many types of large studies, the data are likely to have arisen from multiple centers, resulting in a withinâcenter correlation for the response. Such correlation, or clustering, occurs when outcomes within centers tend to be more similar to each other than to outcomes in other centers. In studies where there is also variability among centers with res ...
 DOI:
 10.1111/j.0006341X.1999.00470.x

http://dx.doi.org/10.1111/j.0006341X.1999.00470.x
 Author:
 Goggins, William B.; Finkelstein, Dianne M.; Zaslavsky, Alan M.
 Source:
 Biometrics 1999 v.55 no.2 pp. 445451
 ISSN:
 0006341X
 Subject:
 Human immunodeficiency virus; algorithms; biometry; data collection; models; patients; risk groups; screening
 Abstract:
 ... This paper develops methodology for estimation of the effect of a binary time‐varying covariate on failure times when the change time of the covariate is interval censored. The motivating example is a study of cytomegalovirus (CMV) disease in patients with human immunodeficiency virus (HIV) disease. We are interested in determining whether CMV shedding predicts an increased hazard for developing a ...
 DOI:
 10.1111/j.0006341X.1999.00445.x

http://dx.doi.org/10.1111/j.0006341X.1999.00445.x
 Author:
 Lee, Jae Kyun; Lascoux, Martin; Newton, Michael A.; Nrdheim, Erik V.
 Source:
 Biometrics 1999 v.55 no.2 pp. 376386
 ISSN:
 0006341X
 Subject:
 Brassica rapa; Markov chain; algorithms; biometry; genetics; genotype; lethal genes; models; mortality; outcrossing
 Abstract:
 ... The characteristics of deleterious genes have been of great interest in both theory and practice in genetics. Because of the complex genetic mechanism of these deleterious genes, most current studies try to estimate the overall magnitude of mortality effects on a population, which is characterized classically by the number of lethal equivalents. This number is a combination of several parameters, ...
 DOI:
 10.1111/j.0006341X.1999.00376.x

http://dx.doi.org/10.1111/j.0006341X.1999.00376.x
 Author:
 Sinha, Debajyoti; Chen, MingâHui; Ghosh, Sujit K.
 Source:
 Biometrics 1999 v.55 no.2 pp. 585590
 ISSN:
 0006341X
 Subject:
 Bayesian theory; biometry; breast neoplasms; data collection; models; patients; statistical analysis
 Abstract:
 ... Intervalâcensored data occur in survival analysis when the survival time of each patient is only known to be within an interval and these censoring intervals differ from patient to patient. For such data, we present some Bayesian discretized semiparametric models, incorporating proportional and nonproportional hazards structures, along with associated statistical analyses and tools for model sel ...
 DOI:
 10.1111/j.0006341X.1999.00585.x

http://dx.doi.org/10.1111/j.0006341X.1999.00585.x
 Author:
 Simon, Richard
 Source:
 Biometrics 1999 v.55 no.2 pp. 484487
 ISSN:
 0006341X
 Subject:
 Bayesian theory; clinical trials; confidence interval; drug therapy; heart diseases; human diseases; models; planning
 Abstract:
 ... We consider the design and analysis of active control clinical trials, i.e., clinical trials comparing an experimental treatment E to a control treatment C considered to be effective. Direct comparison of E to placebo P, or no treatment, is sometimes ethically unacceptable. Much discussion of the design and analysis of such clinical trials has focused on whether the comparison of E to C should be ...
 DOI:
 10.1111/j.0006341X.1999.00484.x

http://dx.doi.org/10.1111/j.0006341X.1999.00484.x
 Author:
 Follmann, Dean A.; Albert, Paul S.
 Source:
 Biometrics 1999 v.55 no.2 pp. 603607
 ISSN:
 0006341X
 Subject:
 biometry; blood; monitoring
 Abstract:
 ... A Bayesian approach to monitoring event rates with censored data is proposed. A Dirichlet prior for discrete time event probabilities is blended with discrete survival times to provide a posterior distribution that is a mixture of Dirichlets. Approximation of the posterior distribution via data augmentation is discussed. Practical issues involved in implementing the procedure are discussed and ill ...
 DOI:
 10.1111/j.0006341X.1999.00603.x

http://dx.doi.org/10.1111/j.0006341X.1999.00603.x
 Author:
 Xiao‐Hua, Zhou; Tu, Wanzhu
 Source:
 Biometrics 1999 v.55 no.2 pp. 645651
 ISSN:
 0006341X
 Subject:
 analysis of variance; data collection; precision; reliability
 Abstract:
 ... In this paper, we consider the problem of testing the mean equality of several independent populations that contain log‐normal and possibly zero observations. We first showed that the currently used methods in statistical practice, including the nonparametric Kruskal–Wallis test, the standard ANOVA F‐test and its two modified versions, the Welch test and the Brown–Forsythe test, could have poor Ty ...
 DOI:
 10.1111/j.0006341X.1999.00645.x

http://dx.doi.org/10.1111/j.0006341X.1999.00645.x
 Author:
 Sternberg, Maya R.; Satten, Glen A.
 Source:
 Biometrics 1999 v.55 no.2 pp. 514522
 ISSN:
 0006341X
 Subject:
 algorithms; biometry; models
 Abstract:
 ... Chainâofâevents data are longitudinal observations on a succession of events that can only occur in a prescribed order. One goal in an analysis of this type of data is to determine the distribution of times between the successive events. This is difficult when individuals are observed periodically rather than continuously because the event times are then interval censored. Chainâofâevents ...
 DOI:
 10.1111/j.0006341X.1999.00514.x

http://dx.doi.org/10.1111/j.0006341X.1999.00514.x
 Author:
 Huggins, Richard M.; Yip, Paul S. F.
 Source:
 Biometrics 1999 v.55 no.2 pp. 387395
 ISSN:
 0006341X
 Subject:
 biometry; birds; variance; China
 Abstract:
 ... A weighted martingale method, akin to a moving average, is proposed to allow the use of modified closedâpopulation methods in the estimation of the size of a smoothly changing open population when there are frequent capture occasions. We concentrate here on modifications to martingale estimating functions for model Mt, but a wide range of closedâpopulation estimators may be modified in this fa ...
 DOI:
 10.1111/j.0006341X.1999.00387.x

http://dx.doi.org/10.1111/j.0006341X.1999.00387.x
 Author:
 McDonald, John W.; Smith, Peter W. F.; Forster, Jonathan J.
 Source:
 Biometrics 1999 v.55 no.2 pp. 620624
 ISSN:
 0006341X
 Subject:
 Monte Carlo method; biometry; linear models; mortality
 Abstract:
 ... We propose MetropolisâHastings sampling methods for estimating the exact conditional pâvalue for tests of goodness of fit of logâlinear models for mortality rates and standardized mortality ratios. We focus on twoâway tables, where the required conditional distribution is a multivariate noncentral hypergeometric distribution with known noncentrality parameter. Two examples are presented: a ...
 DOI:
 10.1111/j.0006341X.1999.00620.x

http://dx.doi.org/10.1111/j.0006341X.1999.00620.x
 Author:
 Muthén, Bengt; Shedden, Kerby
 Source:
 Biometrics 1999 v.55 no.2 pp. 463469
 ISSN:
 0006341X
 Subject:
 alcohol abuse; alcoholic beverages; algorithms; growth models; prediction; probability; young adults
 Abstract:
 ... This paper discusses the analysis of an extended finite mixture model where the latent classes corresponding to the mixture components for one set of observed variables influence a second set of observed variables. The research is motivated by a repeated measurement study using a random coefficient model to assess the influence of latent growth trajectory class membership on the probability of a b ...
 DOI:
 10.1111/j.0006341X.1999.00463.x

http://dx.doi.org/10.1111/j.0006341X.1999.00463.x
 Author:
 Satten, Glen A.; Sternberg, Maya R.
 Source:
 Biometrics 1999 v.55 no.2 pp. 507513
 ISSN:
 0006341X
 Subject:
 biometry; models; people
 Abstract:
 ... In a semiâMarkov model, the hazard of making a transition between stages depends on the time spent in the current stage but is independent of time spent in other stages. If the initiation time (time of entry into the network) is not known for some persons and if transition time data are interval censored (i.e., if transition times are not known exactly but are known only to have occurred in some ...
 DOI:
 10.1111/j.0006341X.1999.00507.x

http://dx.doi.org/10.1111/j.0006341X.1999.00507.x